Immunology Flashcards
What are the physcial barriers to infection in the skin?
keratinocytes secrete antimicrobial peptides - defensives
sebaceous/sweat glands secrete microbe inhibiting substances - fatty acids
What are the physcial barriers to infection in the mucosa of the respiratory/GI/GU tract?
antimicrobial substances - lysozyme
secretory IgA
gastric acid
What two immune cells are termed phagocytes?
neutrophils and macrophages
What is the role of phagocytes?
ingest organisms following respiration
What does failure of phagocytes to function lead to?
haemotological malignancy
cytotoxic chemo
What is the role of CD4 T lymphocytes?
activates phagocytes to kill microbes
What is the role of CD8?
destroys infected cells containing microbes or microbial proteins
What are T lymphocyte deficiencies seen in?
HIV infection - aquired CD4 deficiency
lymphoma
primary immunodeficency syndromes
What do B cells mature into and produce?
plasma cells
produce immunoglobulins
Which immunoglobulin is produced first in response to recognised antigens?
IgM
Which immunoglobulin is produced second in response to recognised antigens?
IgG
What diseases are B cell deficiencies seen in?
myeloma
primary immunodeficiency syndromes
How does HIV infections affect the immune system?
infects CD4 cells resulting in cell mediated immunity being deficient
What are HIV patients at a higher risk of?
invasive pneumococcal disease
What antibiotic is given to HIV patients for prophylaxis against infections?
co-trimoxazole
What are pathogens are HIV patients with a CD4 <350 most susceptible to?
mycobacterium tuberculosis
candidiasis
What are pathogens are HIV patients with a CD4 <200 most susceptible to?
pneumocystis jiroveci
toxoplasma gondii
What are pathogens are HIV patients with a CD4 <100 most susceptible to?
cryptococcus neoformans
cytomegalovirus
What can cause hyposplensim?
sickle cell
cirrhosis
coeliac disease
functional hyposplenism
What bugs are patients with hyposplenism most susceptble to?
strep pneumoniae
H.influenzae type B
nisseria menignitis
What are the different features of an old persons immune system?
less complement produced
less antibody produced
What are people on steroids more susceptible to?
fungal infections - aspergillus, candida
What are people on anti TNF therapies more susceptible to?
mycobacterium tuberculosis
aspergillus - fungals
What are people on purine analogues more susceptible to?
pneumocystis jiroveci
viral infections
What is given for prophylaxis against infection in bone marrow transplant patients?
itraxonazole
Who recieves influenza and strep pneumoniae vaccines?
pregnant women
>65
immunocomprimised
chronic heart/kidney/liver/lung/diabetes
Who receives H.influenzae type B vaccination?
all children
